Curtain stretcher



Sept. 14, 1937. c a CARLSQN 2,092,953

CURTAIN SIRETCHER Filed June 5, 1936 Patented Sept. 14, 1937 UNITED}STATES CURTAIN STRETCHER Clarence G. Carlson, Chicago, 111., assignor toChicago Curtain Stretcher Company, Chicago, 11., a corporationof'Illinois Application June 5, 1936, Serial No. 83,623

3 Claims.

This invention relates to curtain stretchers employing side rails (orend rails) which are of such length that it is desirable to make them insections in order to permit the folding of the curtain stretcher intocompact form when it is not set up for use. This requires that the railsections be united in such a manner as to afford a firm and rigidconnection when in use and sulficient reinforcement at the joint toprevent bending or collapse, and at the same time afford means whichwill permit the joint to be quickly broken and which will thereafterserve to hold the two sections in folded relation to one another. Thepresent invention is directed to the means provided for affording aninterlocking connection for the rail sections of extremely simple andrugged construction, which may be manufactured by a simple punch pressoperation andwhich in use will afford abundant rigidity and at the sametime permit the sections to be drawn apart and folded withoutdifiiculty.

Further objects and details will appear from a description of theinvention in conjunction with the accompanying drawing, wherein,

Figure 1 is a plan view of a portion of the curtain stretcher showingthe joint members of the present invention;

Fig. 2 is an edge elevation of the same;

Fig. 3 is a plan view showing the joint broken preparatory to thefolding of the rail sections;

Fig. 4 is a similar view showing the parts in folded relation;

Fig. 5 is a sectional view taken on line 5-5 of Fig. 1;

Fig. 6 is a sectional view taken on line 66 of Fig. 4; and

Fig. 7 is a perspective view showing the joint plates standing in theirintended relation to one another with the rail sections removed.

As shown in Fig. 1, the curtain stretcher of standard type is providedwith side rail sections 1 fl and l 1 which when the stretcher is set upstand in alignment with one another and with their ends in closelyabutting relation. A wooden cross rail 12 traverses the joint betweenthe wooden side rail sections 10 and It, the cross rail being providedwith the usual graduations marked thereon.

The rail section 10 has secured thereto on opposite sides a pair oflocking bars 13 and 14 which are secured by means of rivets 15 passingthrough the wooden rail section and to overlap the end of the railsection II when the two sections stand in butt contact. The locking bar13 is provided near its outwardly projecting end with an open slot 16and the locking bar 14 is of L-shape and the threaded end of the boltreceives a wing nut 1 21 which maybe turned down'to abut against thecross rail 12 and hold the locking bars in tightly clamped relation uponopposite sides of the end of the rail section.- j I The slot !8 in theleg H is of sufiicient length to permit the bolt 19, when loosened, tobe slipped to the outer end of the slotas in Fig. 3, which affords justsufficient clearance to permit the bolt to act as a hinged pintle orpivot forswinging around the side rail sectionl I into parallel folded Zrelation to the section 10, and also permitsa similar folding of thecross rail 12 as in Fig. 4. This permits the elongated side rails of thecurtain stretcher to be folded into convenient compass for storage andalso insures against accidental disassembly of the parts, althoughpermitting such disassembly by the complete removal of the wing nut 21and bolt 19 if occasion requires.

The two locking bars 13 and 14 being stamped from plate metal withoutoffsets or protuberances may be made of comparatively heavy stock by asimple stamping operation which affords great rigidity, and theconnection thus afforded serves to hold the ends of the side rails intoclose butt contact so that a single screw bolt and wing nut will affordabundant friction to maintain the parts in aligned relation during use.This is due to the fact that the proportioning of the parts is such thatthe two rail sections can be brought into aligned relation only by atransverse sliding movement, and the ends of the rails being cut atright angles will thus slip past one another in very close contact, sothat this closeness of fit is relied upon to prevent bending or bucklingat the joint, and the locking elements serve merely to maintain the buttcontact so that additional bracing is unnecessary.

The device is of extremely simple construction and has been founddistinctly superior to more complicated devices employing hingeconnections or the like.

Although the connection hereinbefore described possesses substantialadvantages for use in locking the rail joints of a curtain stretcher, itis also adapted for use under circumstances in which a like connectionis required.

I claim:

1. In a curtain stretcher or the like, the combination of rail sectionsstanding in end abutment with one another, one of the sections beingprovided on opposite sides with forwardly projecting locking barsextending past the jointbetween the rail sections and adapted to embracethe companion rail section, each of the locking bars being provided witha transverse slot the slots extending in parallel relation and, at leastone of said slots being closed at its outer end, a connecting memberentered through the, two slots and through the last named rail section,and locking means on the connecting member for holding the locking barsin locked relation across the joint between the rail sections, the slotsbeing spaced from the end of the member which carries the locking barsat a distance sufiicient to prevent longitudinal movement of thesections from the position establishing close butt contact and theclosed slot being of suflicient length to permit lateral movement of therail sections and to permit theabutting ends to slip past one another tothe degree necessary to permit folding of the structure.

2. In a curtain stretcher or the like, the combination of side railsnormally adapted to stand in end abutting relation to one another, oneof the sections being provided on opposite sides with locking barsprojecting forwardly therefrom in position to embrace the sides of thecompanion rail section near the end thereof, one of the locking barsbeing provided within its projecting end with a transversely extendingopen slot and the other locking bar being provided with a laterallyextending leg having therein an elongated slot parallel with the firstmentioned slot and closed 0 at its outer end, a bolt entered through thecompanion rail section and through the slots in the locking bars, andthe'slots being spaced from the end of the section which carries thelocking bars in a degree sufficient to prevent longitudinal movement ofthe sections from the position establishing close butt contact, andscrew means on the bolt for holding the locking bars in clampingrelation across the joint between the rail sections, the elongated slotbeing configured to permit the rail sections to be moved laterally andthe abutting ends to slippast one another without longitudinaldisplacement to the degree necessary to permit folding of the structure.

3. In a curtain stretcher or the like, the combination of side railsnormally adapted to stand in end abutting relation to one another, oneof the sections being provided on opposite sides with locking barsprojecting forwardly therefrom in position to embrace the sides of thecompanion rail section near the end thereof, one of the locking barsbeing provided within its projecting end with a transversely extendingopen slot and the other locking bar being provided with a laterallyextending leg having therein an elongated slot parallel with the firstmentioned slot and closed at its outer end, a bolt entered through thecom panion rail section and through the slots in the locking bars, andthe slots being spaced from the end of the section which carries thelocking bars in a, degree sufficient to prevent longitudinal movement ofthe sections from the position establishing close butt contact, means onthe bolt for holding the locking bars in clamping relation across thejoint between the rail sections, the elongated slot being configured topermit the rail sections to be movedlaterally and the abutting ends toslip past one another without longitudinal displacement to the degreenecessary to permit folding of the structure, and a cross rail abuttingagainst the outer face of the angularly disposed slot lock and havingthe bolt entered therethrough and adapted to pivot on said bolt topermit folding.

CLARENCE G. CARLSON.

